In the prior art, different connection inserts are known, in particular threaded inserts. Depending on the component materials in which such a component insert shall be fastened, the configuration of the shape of such a connection insert varies. U.S. Pat. No. 6,676,352 B2, for example, discloses a threaded insert, which can be screwed or driven into a pre-drilled hole of a wood component. To this end, this connection insert comprises on its radially outer side threadlike extending ribs that cut into the wood of the component. This connection insert is, thus, constructed similar to a wood screw and, therefore, not suitable for plastic components.
Generally, it is known to embed connection inserts into already formed plastic components. Such an embedding is done by supplying heat to the plastic component so that the plastic is plasticized locally. The connection insert is then pressed into this plasticized plastic so that it is fastened in the plastic component after hardening or curing of the plastic. For such embeddable connection inserts, various constructions are known in the prior art. WO 2011/130070 A1 describes, for example, an embeddable connection insert having a cylindrical main body with a radially outer side. At this radially outer side, circumferentially wavelike extending radially protruding webs are arranged. During the embedding of the connection insert, i.e. while pressing the connection insert in axial direction into the plasticized plastic, these radial protruding webs push plasticized plastic in front of them. As the plasticized plastic cools down during the inserting of the connection insert and has also a poor flow behavior, only a portion of the intermediate spaces between the wavelike extending webs is filled with plasticized plastic. This means that the connection insert has only a low axial security against extraction.
Another connection insert is described in WO 2011/109236 A1. Here, the radially protruding webs arranged at the radially outer side of the cylindrical main body also extend in wave form. In addition, these webs are arranged with an inclination in the axial direction. It follows that with respect to an axial extraction direction, also these webs which approximately extend in axial direction, can only provide a limited extraction strength.
WO 2011/130073 A1 describes an embeddable connection insert having a plurality of protruding locking noses on its radially outer side. These locking noses are formed tapered in axial insert direction of the connection insert for facilitating the embedding. Contrary to the extraction direction, these locking noses comprise supporting surfaces oriented approximately perpendicular to the extraction direction. Compared to the remaining surface of the radially outer side, these supporting surfaces are, however, formed small so that no complete back-flowing of the plasticized plastic can take place due to its high surface tension. Thus, at the same time, the curing plastic does not sufficiently lock the connection insert in the plastic component.
A further connection insert, especially a threaded insert, is described in DE 100 13 091 A1. While a radially circumferential collar is arranged at one end, a plurality of successive conical sections are arranged on the radially outer side of the cylindrical main body. These conical sections taper in the axial insertion direction of the threaded insert. In this way, a plurality of radially circumferential surfaces is formed, which could form an undercut and, thus, a security against extraction. However, as here also only a slow flowing of the plasticized plastic takes place during the embedding, the plasticized plastic flows only incompletely behind the here formed radially circumferential edges. This is partly because the flow channels for the plasticized plastic extending in axial direction cover only small portions of the radially outer side of the main body. A further disadvantage is that an axial security against extraction is provided but the axial strength in insertion direction is given only in a limited way. This is partly because the conically formed radially outer side of the main body supports an axial insertion of the threaded insert into the plastic component.
One object that may be achieved by at least some implementations of the present invention is to provide an embeddable connection insert which is installable with a more reliable security against extraction compared to the prior art.